Background: Recent studies demonstrated that patients with advanced cancer may have impaired cell-mediated immunity caused by an imbalance between Th1 and Th2 responses. We evaluated the ability of lentinan (LNT) to modulate Th1 and Th2 responses in patients with digestive cancers.
Methods: Peripheral blood samples were collected preoperatively from 28 patients with digestive cancers before and after intravenous administration of LNT (2 mg x 3 times/week). The proportions of CD4+ T-cells producing intracellular cytokines were determined with flow cytometry.
Results: After LNT treatment, CD4+ IFN-gamma+ T-cell percentages increased significantly (p < 0.05), whereas CD4+ IL-4+ T-cell and CD4+ IL-6+ T-cell percentages decreased significantly (p < 0.02). No significant change occurred in proportions of CD4+ IL-10+ T-cells. The after/before LNT treatment percentages ratio of CD4+ IFN-gamma+ T-cells correlated negatively with that of CD4+ IL-4+ T-cells (p < 0.01). The after/before treatment percentage ratio of CD4+ IL-4+ T-cells correlated positively with that of CD4+ IL-6+ T-cells (p < 0.05).
Conclusion: LNT apparently can cancel Th2-dominant condition in patients with digestive cancers and may improve the balance between Th1 and Th2.